Internal bead trimmers

ABSTRACT

An internal bead trimmer for removing the internal bead formed in the production of welded metal tube, in which the trimmer is mountable for relative axial movement within a tube. The trimmer includes: a bead cutting member; a measuring jet orifice carried by the trimmer downstream of the bead cutting member, said measuring jet orifice being connectable to a source of fluid pressure; and means for enabling the fluid pressure at the outlet of the measuring jet to be sensed; said orifice being so arranged and disposed that in use it follows the path of the cutting member at a predetermined spacing from the internal tube wall and directed at the weld line.

Unite State's ate nt [191 Bosworth Jan. 0, 19741 1 INTERNAL BEA!)TRlMMERS 2,714,338 8/1955 Nance 90/24 B [75] Inventor: gg i z gj iigBosworth Primary Examiner-Andrew R. Juhasz g Assistant lj q ngzgr w. D.Bray [73] Assignee: British Steel Corporation, London, Attorney- BacontTThoiri a s England 22 Filed: Aug. 28, 1972 1 ABSTRACT Appl. No.:284,080

Foreign Application Priority Data An internal bead trimmer for removingthe internal bead formed in the production of welded metal tube, inwhich the trimmer is mountable for relative axial movement within atube. The trimmer includes: a bead cutting member; a measuring jetorifice carried by the trimmer downstream of the bead cutting memher,said measuring jet orifice being connectable to a source of fluidpressure; and means for enabling the fluid pressure at the outlet of themeasuring jet to be sensed; said orifice being so arranged and disposedthat in use it follows the path of the cutting member at a predeterminedspacing from the internal tube wall and directed at the weld line.

13 Claims, 3 Drawing Figures PM'ENTED N 8 974 mm 7 In! INTERNAL BEAT)TRTMMERS This invention relates to internal bead trimmers for trimmingthe internal bead of excess metal formed along the weld line in theproduction of electric longitudinally welded tube.

In the manufacture of electric welded tube, the electrically heatedlongitudinal edges of metal strip are forced together to form a seamweld, and in so doing a certain amount of metal is squeezed inwardly andoutwardly of the tube to form ridges or beads which vary in thicknessdepending on the tube size, the wall thickness, and welding conditions.To make an acceptable final tube product it is necessary that thesebeads be accurately and evenly trimmed off flush with the internal andexternal surfaces of the tube.

In the case of removal of the internal bead, it is known to provide acutting tool or trimmer mounted on a trimmer head assembly locatedfirmly on wheels in the bore of the tube.

It is an object of the present invention to provide means forcontrolling or monitoring the operation of such a trimmer.

According to the present invention there is provided an internal beadtrimmer for removing the internal bead formed in the production ofwelded metal tube, said trimmer being mountable for movement within atube and including a bead cutting member; a measuring jet orificecarried by the trimmer downstream of the bead cutting member, saidmeasuring jet orifice being connectable to a source of fluid pressure;and means for enabling the fluid pressure at the outlet of the measuringjet orifice to be sensed; said orifice being so arranged and disposedthat in use it follows the path of the cutting member at a predeterminedspacing from the internal tube wall and directed at the weld line.

The invention is based upon the fact that, assuming a constant pressurefluid supply, the pressure at the orifice outlet will vary in dependenceon the spacing of the orifice outlet from the internal tube wall withina certain range of that spacing, so that if the radial location of theorifice within the metal tube generally is kept constant, variations inthe orifice outlet pressure are dependent on the amount of beadremaining along the weld line after trimming. Hence the efficiency,consistency and effectiveness of the trimming operation can bemonitored.

Means may be provided for adjusting the position of the cutting memberfor optimum performance. Such means may be arranged for use duringoperation of the trimmer in dependence on the measuring orifice pressurereadings and may comprise a mechanical linkage.

A second, annular, orifice may be provided surrounding the measuring jetorifice, the second orifice being subjected, in use, to a higher fluidpressure than the measuring jet orifice, such that laminar flow existsin the fluid streams leaving the orifices whereby the two streams do notmix. By this means the inner measuring stream is still radiallyrestricted beyond the end of its orifice outlet by the annular jetencircling it, so that effective working of the arrangement is possibleat greater spacing between the measuring orifice and the tube wall thanwould be otherwise possible. Hence the danger of orifice being hit anddamaged by an excessively protruding portion of the internal bead orother inward protrusion is diminished compared with the case where onlya single, measuring, orifice is used.

The inner measuring orifice and the outer annular orifice may beconnectable to a single compressed fluid supply pipe, the differentialpressure therebetween in use, being provided by means, for example, ofan apertured pressure reducing baffle in an inlet pipe leading to atleast one of the orifices.

The fluid used for the jet orifice or orifices may be air.

In order that the invention may be more fully understood two embodimentsthereof will now be described by way of example with reference to theaccompanying drawings in which:

FIG. 1 is a diagrammatic side elevation of part of one form of beadtrimmer according to the invention;

FIG. 2 is a diagrammatic representation of the pneumatic arrangement ofthe embodiment of FIG. 1; and

FIG. 3 is a diagrammatic representation of the pneumatic arrangement ofan alternative embodiment of the invention.

Referring now to FIGS. l and 2, it will be seen that the trimmercomprises a head assembly or main body 1 mounted on four wheels 2,3, 4and 5 for movement relative to a welded tube 6. In practice the trimmeris held stationary by means of an elongate rod (not shown) inserted intothe tube from upstream of the tube welding station and connected to thetrimmer by means of lug 7, whilst the welded tube is continuously movedpast the trimmer in the direction of arrow 8 to further operationalstations whereat it is cut into required lengths and subjected tofurther known finishing processes.

The wheels 2 and 3 are provided with peripheral grooves (not shown) forengaging the internal bead formed along the tube weld line, so that thetrimmer is radially aligned within the tube 6.

The trimmer carries an adjustable cutting member 9 which engages withand removes the internal bead 10 which, after being cut, passes throughthe body I and along the inside of the tube 6 to be removed at the nextoperating station where the tube is cut into required lengths.

Carried behind the main body ll of the trimmer is a bogey member llllwhich is mounted for free rotation on a bearing 12 carried by the bodyll, and has two pairs of wheels (two only shown) 13 and M, each pairbeing mounted on axles l5 and 16 respectively. Mounted on the bogey 111between the wheels 13 and M is a measuring jet orifice l7 directedtoward the tube weld line (i.e., at the remnant of the cut bead) andspaced therefrom by a distance of up to about 0.015 inch or 0.020 inch.The orifice 17 is connected bya pipe 18 to an air source (not shown) andthe arrangement is such that air is emitted from the orifice at apressure of the order of 1 psi.

The pneumatic monitoring arrangement of the trimmer of FIG. 11 is shownin FIG. 2.

Air from a source (not shown) passes through a pressure reducing baffle19, and then towards the pipe 10. A branch pipe 20 is connected to apressure gauge 21 which measures variations of pressure in the pipe 18.Within the range of spacing of the orifice 17 from the weld line alongthe tube wall 6 used in the trimmer, such pressure variations aredependent on variations in that spacing. Hence by suitable calibrationof the pressure gauge 2T, it is possible to monitor from the gaugewhether or not the bead is being correctly trimmed.

The arrangement shown in FIGS. 1 and 2 is in many instances completelysatisfactory. However the very close spacing of the orifice 17 from tubewall can involve problems in some cases in that inwardly directedprotrusions or similar blemishes can possibly hit and damage theorifice.

The arrangement shown in FIG. 3 reduces this particular problem.

In this embodiment, in addition to the measuring jet orifice 17 there isprovided a further annular orifice 22 surrounding the measuring orifice.As before, the measuring orifice is connected to a pressure gauge 21 andto an air supply via a pressure reducing baffle. In this case howeverthe air supply is also connected via a pipe 23 to the annular orifice22. In practice, the pressure of the annular jet is of the order of 4.p.s.i., and of the innerjet about 1 p.s.i. It is found that the two jetsmaintain laminar flow and do not mix, and the annular jet acts as aconstraining cylinder around the inner jet so that the orifice 17 may bespaced further from the inner tube wall (more particularly from the weldline) with the dependence of inner jet pressure variation on spacingstill holding true.

Means, generally indicated by the reference numeral 31, for adjustingthe position of the cutting member for optimum performance duringoperation of the trimmer in dependence on the measuring orifice pressurereadings, may comprise a mechanical linkage 33. In this case a spacingof up to about 0.100 inch is possible.

I claim:

1. An internal bead trimmer for removing the internal bead formed in theproduction of welded metal tube, said trimmer being mountable forrelative axial movement within a tube, and said trimmer including: abead cutting member; a measuring jet orifice carried by the trimmerdownstream of the bead cutting member, said measuring jet orifice beingconnectable to a source of fluid pressure; and means for enabling thefluid pressure at the outlet of the measuring jet to be sensed; saidorifice being so arranged and disposed that in use it follows the pathof the cutting member at a predetermined spacing from the internal tubewall and directed at the weld line.

'2. A bead trimmer as claimed in claim 1 in which the measuring jetorifice is connectable to a pressure gauge.

3. A bead trimmer as claimed in claim 1 including means for adjustingthe position of the cutting member.

4. A bead trimmer as claimed in claim 3 in which the means for adjustingthe position of the cutting member is operable in use of the trimmer.

5. A bead trimmer as claimed in claim 1 in which the measuring jetorifice is connectable to a supply of compressed air.

6. A bead trimmer as claimed in claim 1 in which the orifice is mountedon a wheeled bogey carried behind the cutting member.

7. An internal bead trimmer for removing the internal bead formed in theproduction of welded metal tube, said trimmer being mountable forrelative axial movement within a tube, and said trimmer including: abead cutting member; a measuring jet orifice and a separate annularorifice surrounding the measuring jet orifice, said measuring jetorifice and said annular orifice being each connectable to a source offluid pressure, and the annular orifice being arranged to be subjected,in use, to a higher fluid pressure than the measuring jet orifice suchthat laminar flow exists in the fluid streams leaving the orificeswhereby the two streams do not mix; and means for enabling the fluidpressure at the outlet of the measuring jet orifice to be sensed; saidorifices being so arranged and disposed that in use they follow the pathof the cutting member at a predetermined spacing from the internal tubewall and directed at the weld line.

8. A bead trimmer as claimed in claim 7 in which the measuring orificeand the annular orifice are connectable to a single compressed fluidsupply pipe, differential pressure therebetween in use, being providedby means of an apertured pressure reducing baffle in an inlet pipeleading to at least one of the orifices.

9. A bead trimmer as claimed in claim 7 in which the measuring jetorifice is connectable to a pressure gauge.

10. A bead trimmer as claimed in claim 7 including means for adjustingthe position of the cutting member.

11. A bead trimmer as claimed in claim 10 in which the means foradjusting the position of the cutting member is operable in use of thetrimmer.

12. A bead trimmer as claimed in claim 7 in which the measuring jetorifice is connectable to a supply of compressed air.

13. A bead trimmer as claimed in claim 7 in which the orifices aremounted on a wheeled bogey carried the cutting member.

1. An internal bead trimmer for removing the internal bead formed in theproduction of welded metal tube, said trimmer being mountable forrelative axial movement within a tube, and said trimmer including: abead cutting member; a measuring jet orifice carried by the trimmerdownstream of the bead cutting member, said measuring jet orifice beingconnectable to a source of fluid pressure; and means for enabling thefluid pressure at the outlet of the measuring jet to be sensed; saidorifice being so arranged and disposed that in use it follows the pathof the cutting member at a predetermined spacing from the internal tubewall and directed at the weld line.
 2. A bead trimmer as claimed inclaim 1 in which the measuring jet orifice is connectable to a pressuregauge.
 3. A bead trimmer as claimed in claim 1 including means foradjusting the position of the cutting member.
 4. A bead trimmer asclaimed in claim 3 in which the means for adjusting the position of thecutting member is operable in use of the trimmer.
 5. A bead trimmer asclaimed in claim 1 in which the measuring jet orifice is connectable toa supply of compressed air.
 6. A bead trimmer as claimed in claim 1 inwhich the orifice is mounted on a wheeled bogey carried behind thecutting member.
 7. An internal bead trimmer for removing the internalbead formed in the production of welded metal tube, said trimmer beingmountable for relative axial movement within a tube, and said trimmerincluding: a bead cutting member; a measuring jet orifice and a separateannular orifice surrounding the measuring jet orifice, said measuringjet orifice and said annular orifice being each connectable to a sourceof fluid pressure, and the annular orifice being arranged to besubjected, in use, to a higher fluid pressure than the measuring jetorifice such that laminar flow exists in the fluid streams leaving theorifices whereby the two streams do not mix; and means for enabling thefluid pressure at the outlet of the measuring jet orifice to be sensed;said orifices being so arranged and disposed that in use they follow thepath of the cutting member at a predetermined spacing from the internaltube wall and directed at the weld line.
 8. A bead trimmer as claimed inclaim 7 in which the measuring orifice and the annular orifice areconnectable to a single compressed fluid supply pipe, differentialpressure therebetween in use, being provided by means of an aperturedpressure reducing baffle in an inlet pipe leading to at least one of theorifices.
 9. A bead trimmer as claimed in claim 7 in which the measuringjet orifice is connectable to a pressure gauge.
 10. A bead trimmer asclaimed in claim 7 inclUding means for adjusting the position of thecutting member.
 11. A bead trimmer as claimed in claim 10 in which themeans for adjusting the position of the cutting member is operable inuse of the trimmer.
 12. A bead trimmer as claimed in claim 7 in whichthe measuring jet orifice is connectable to a supply of compressed air.13. A bead trimmer as claimed in claim 7 in which the orifices aremounted on a wheeled bogey carried the cutting member.